This invention relates generally to an electrostatographic printer or copier, and more particularly concerns a cleaning apparatus used therein.
In an electrostatographic reproducing apparatus, a latent electrostatic information image is formed on an electrically insulating carrier. The latent image is developed into a visible image by the application of toner particles to the carrier surface, whereby the particles are caused to adhere electrostatically either to the portions of the carrier surface that are electrostatically charged or to the portions that are not charged and the adhered toner particles may then be transferred imagewise to an image receiving or record sheet. After the transfer, the insulating carrier is cleaned of residual toner particles and freed of the image charge pattern, and then reused in the production of another image.
Effective and efficient cleaning of the residual particles (i.e. toner and other debris) from the insulating carrier is a critical operation, since any such residual particles will interfere with a subsequent image developed on the carrier. At the same time, it is important that the cleaning operation not damage the image carrier surface. Cylindrical brushes such as an electrostatic brush are commonly used in this type of cleaning operation.
The basic function of the electrostatic brush cleaner is to carry a controlled voltage bias to remove charged toner from the photoreceptor surface. However, in cleaning the photoreceptor surface, residual particles of toner and other debris accumulate on the ground strip located along the edge(s) of the photoreceptor. This accumulation or build-up of residual particles can lead to print or copy quality defects if not removed. By its basic design, the electrostatic brush cleaner can not be used to clean the ground strip because it will short out to the grounded surface causing a print or copy quality defect.